request mechanism helpers added and few other small changes

.gitignore

@@ -1,4 +1,5 @@
 *.png
 __pycache__/
 etcd3_wrapper
-
+.idea
+.vscode

docs/ucloud-general-working (current).dot

@@ -0,0 +1,56 @@
+digraph G{
+
+    rankdir=TB;
+    start [shape=point];
+    ucloud_api [style=filled,color=white];
+    start -> ucloud_api [label="User Requests to Start VM 'vm1'"];
+
+    subgraph cluster_common {
+        style=filled;
+		color=lightgrey;
+        RequestQueue [shape=rect, style=filled, color=plum1];
+
+    }
+
+
+    subgraph cluster_api {
+    style=filled;
+		color=lightgrey;
+        		node [style=filled,color=white];
+
+        ucloud_api -> RequestQueue [label="RequestQueue.append(Request)        "]
+    }
+    
+
+    subgraph cluster_scheduler {
+        rankdir=RL;
+        style=filled;
+		color=lightgrey;
+		node [style=filled,color=white];
+        label="ucloud-scheduler";
+
+        PENDING_REQUESTS [shape=rect, color=peachpuff]
+
+        RequestQueue -> FindHost [label="Get StartVM Requests Only"];
+        FindHost -> PENDING_REQUESTS [constraint=false, color=red, label="append this requests to pending requests"];
+        FindHost -> RequestQueue [label="RequestQueue.append(RunVmRequest(vm='vm1'))", color=darkgreen];
+        PENDING_REQUESTS -> FindHost [label="On Timeout Event.\n Try to fulfil the request again"]
+
+    }
+
+    subgraph cluster_vm {
+        rankdir=RL;
+        style=filled;
+		color=lightgrey;
+		node [style=filled,color=white];
+        label="ucloud-vm";
+
+        VmTrash [shape=point, color=red]
+
+        RequestQueue -> HandleRequest [label="Get Requests for VM Operations"]
+        HandleRequest -> Running [label="RunVMRequest", color=darkgreen]
+        HandleRequest -> Stopped [label="ShutdownVMRequest", color=darkgreen]
+        HandleRequest -> VmTrash [constraint=false, color=red, label="Put error message into VM's log"]
+    }
+    
+}

helpers.py

@@ -1,8 +1,10 @@
-from .etcd3_wrapper import EtcdEntry
+import socket
+import logging
+
+from etcd3_wrapper import EtcdEntry
 
 
 class SpecificEtcdEntryBase(object):
-
     def __init__(self, e: EtcdEntry):
         self.key = e.key
 
@@ -19,7 +21,22 @@ class SpecificEtcdEntryBase(object):
         return self.original_keys()
     
     def __repr__(self):
-        _return = f"""{self.key}"""
-        for key in self.original_keys():
-            _return += f",{key} = {self.__getattribute__(key)}"
-        return _return
+        return str(dict(self.__dict__))
+
+
+def get_ipv4_address():
+    # If host is connected to internet
+    #   Return IPv4 address of machine
+    # Otherwise, return 127.0.0.1
+    with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
+        try:
+            s.connect(("8.8.8.8", 80))
+        except socket.timeout:
+            address = "127.0.0.1"
+        except Exception as e:
+            logging.getLogger().exception(e)
+            address = "127.0.0.1"
+        else:
+            address = s.getsockname()[0]
+
+    return address

host.py

@@ -1,6 +1,9 @@
+from typing import List
+
 from .helpers import SpecificEtcdEntryBase
 from .etcd3_wrapper import EtcdEntry
 from datetime import datetime
+from os.path import join
 
 
 class HostStatus(object):
@@ -39,13 +42,16 @@ class HostPool(object):
         self.prefix = host_prefix
 
     @property
-    def hosts(self):
+    def hosts(self) -> List[HostEntry]:
         _hosts = self.client.get_prefix(self.prefix, value_in_json=True)
         return [HostEntry(host) for host in _hosts]
 
     def get(self, key):
+        if not key.startswith(self.prefix):
+            key = join(self.prefix, key)
         v = self.client.get(key, value_in_json=True)
-        return HostEntry(v)
+        if v:
+            return HostEntry(v)
 
     def put(self, obj: HostEntry):
         self.client.put(obj.key, obj.value, value_in_json=True)

request.py

@@ -0,0 +1,39 @@
+import json
+from etcd3_wrapper import Etcd3Wrapper, EtcdEntry, PsuedoEtcdEntry
+from uuid import uuid4
+from .helpers import SpecificEtcdEntryBase
+from os.path import join
+
+
+class RequestType(object):
+    CreateVM = "CreateVM"
+    ScheduleVM = "ScheduleVM"
+    StartVM = "StartVM"
+    StopVM = "StopVM"
+    InitVMMigration = "InitVMMigration"
+    TransferVM = "TransferVM"
+    DeleteVM = "DeleteVM"
+
+
+class RequestEntry(SpecificEtcdEntryBase):
+    def __init__(self, e: EtcdEntry):
+        self.type = ""
+        super().__init__(e)
+
+    @classmethod
+    def from_scratch(cls, **kwargs):
+        e = PsuedoEtcdEntry(join("/v1/request/", uuid4().hex), value=json.dumps(kwargs).encode("utf-8"),
+                            value_in_json=True)
+        return cls(e)
+
+
+class RequestPool(object):
+    def __init__(self, etcd_client, request_prefix):
+        self.client = etcd_client
+        self.prefix = request_prefix
+
+    def put(self, obj: RequestEntry):
+        if not obj.key.startswith(self.prefix):
+            obj.key = join(self.prefix, obj.key)
+
+        self.client.put(obj.key, obj.value, value_in_json=True)

test.py

@@ -1,13 +0,0 @@
-from vm import VmPool
-from etcd3_wrapper import Etcd3Wrapper
-
-client = Etcd3Wrapper()
-vm_pool = VmPool(client, "/v1/vm")
-# vms = vm_pool.by_status("REQUESTED_NEW")
-# for vm in vms:
-#     print(vm)
-#     print()
-
-v = vm_pool.get("/v1/vm/8402926c7a164966982eae48b2d6d1a9")
-# print(dir(v))
-print(v)

vm.py

@@ -1,23 +1,21 @@
+from contextlib import contextmanager
+from datetime import datetime
 from etcd3_wrapper import EtcdEntry
 from .helpers import SpecificEtcdEntryBase
+from os.path import join
 
 
 class VMStatus(object):
     # Must be only assigned to brand new VM
     requested_new = "REQUESTED_NEW"
 
-    # Host assigned to VM but not created yet.
-    scheduled_deploy = "SCHEDULED_DEPLOY"
-
     # Only Assigned to already created vm
     requested_start = "REQUESTED_START"
 
     # These all are for running vms
     requested_shutdown = "REQUESTED_SHUTDOWN"
-    requested_suspend = "REQUESTED_SUSPEND"
-    requested_resume = "REQUESTED_RESUME"
     requested_migrate = "REQUESTED_MIGRATE"
-
+    requested_delete = "REQUESTED_DELETE"
     # either its image is not found or user requested
     # to delete it
     deleted = "DELETED"
@@ -26,12 +24,6 @@ class VMStatus(object):
     killed = "KILLED"  # either host died or vm died itself
 
     running = "RUNNING"
-    suspended = "SUSPENDED"
-
-
-RUNNING_VM_STATUSES = [VMStatus.requested_shutdown, VMStatus.requested_suspend,
-                       VMStatus.requested_resume, VMStatus.requested_migrate,
-                       VMStatus.running, VMStatus.suspended]
 
 
 class VMEntry(SpecificEtcdEntryBase):
@@ -41,18 +33,33 @@ class VMEntry(SpecificEtcdEntryBase):
         self.hostname = ""
         self.status = ""
         self.image_uuid = ""
-        
+        self.log = []
+        self.in_migration = False
         super().__init__(e)
-   
+
     @property
     def uuid(self):
         return self.key.split("/")[-1]
 
     def declare_killed(self):
         self.hostname = ""
-        if self.status in RUNNING_VM_STATUSES:
+        self.in_migration = False
+        if self.status == VMStatus.running:
             self.status = VMStatus.killed
 
+    def declare_stopped(self):
+        self.hostname = ""
+        self.in_migration = False
+        self.status = VMStatus.stopped
+
+    def add_log(self, msg):
+        self.log = self.log[:5]
+        self.log.append(f"{datetime.now().isoformat()} - {msg}")
+
+    @property
+    def path(self):
+        return f"rbd:uservms/{self.uuid}"
+
 
 class VmPool(object):
     def __init__(self, etcd_client, vm_prefix):
@@ -80,8 +87,19 @@ class VmPool(object):
         return list(filter(lambda x: x.status != status, _vms))
 
     def get(self, key):
+        if not key.startswith(self.prefix):
+            key = join(self.prefix, key)
         v = self.client.get(key, value_in_json=True)
-        return VMEntry(v)
-    
+        if v:
+            return VMEntry(v)
+
     def put(self, obj: VMEntry):
         self.client.put(obj.key, obj.value, value_in_json=True)
+
+    @contextmanager
+    def get_put(self, key) -> VMEntry:
+        # Updates object at key on exit
+        obj = self.get(key)
+        yield obj
+        if obj:
+            self.put(obj)